Cables are often used to connect sub-systems together in a computer such as in a personal computer (PC). For example, the video display monitor may connect to the main PC box using a video display cable, or a video camera may upload video to the PC over a video adapter cable.
The two plug connectors on the ends of the video cable often differ in physical size, shape, and pin arrangement. Different protocol and plug standards may be used for the different ends of the cable. A small circuit board or chip may be embedded within the cable or with one of its plugs to convert signals, or simple cross-over wiring or connections may be used for format conversion.
FIG. 1 shows a prior art dongle. Sometimes the length of the cables are shortened to form a dongle. The dongle is used as an adapter between a longer cable and a plug in a PC or other device. The dongle converts plug formats, allowing the longer cable to use the same connector on both ends.
Digital Visual Interface (DVI) connector 16 connects to a DVI plug in a PC or other device. DVI is a standard developed by the Digital Display Working Group especially for carrying uncompressed digital data to a flat panel display or to a digital projector, rather than to an analog cathode-ray tube (CRT) display. DVI connectors have 29 pins and can carry red, blue, and green signals, either in digital or analog formats, along with a clock to sync the signals. Other information may be carried, such as configuration or display data channel. Transition-minimized differential signaling (TMDS) is used for higher bandwidth using differential signals, such as true (+) and complement (−) clock signals.
Display Port (DP) connector 18 connects to a display port receptacle or plug on a PC or on a display device. Display Port (DP) is a new standard from the Video Electronics Standards Association (VESA) for a digital audio/video interconnect. DP is especially useful for connecting a PC to a display monitor or to a home theater system. Transfer rates of 1.62 or 2.7 gigabits per second are currently supported, with 8 or 10 bit pixels per color channel. Encryption and digital-rights-management (DRM) is optionally supported.
The physical sizes and shapes of DVI connector 16 and DP connector 18 differ, with DVI connector 16 being larger than DP connector 18. DVI housing 10 supports DVI connector 16, while DP housing 12 supports DP connector 18. Flexible cable 14 between DP housing 12 and DVI housing 10 allows the user to grab DP housing 12 and insert DP connector 18 into a cable when DVI connector 16 is plugged into a PC.
The flexibility of cable 14 helps compensate for the difference in physical sizes of DVI connector 16 and DP connector 18, since the exact location of DVI connector 16 can move somewhat. However, the relatively limited movement of round flexible cable 14, especially when cable 14 is short, restricts the use of the dongle, as adjacent plugs on the PC next to the plug that DP connector 18 is plugged into can be blocked by the dongle.
FIG. 2 shows a prior-art fixed adapter. Rather than form a dongle with a flexible cable, the adapter can be formed as a rigid unit. Thumbscrews 22 in rigid body 20 can be screwed into holes in the PC or display device to secure DVI connector 16 into the matching plug or receptacle in the PC. DP connector 18 is fixed to the back of rigid body 20, allowing a cable to be plugged in.
However, when DP connector 18 is plugged into a PC, the larger size of DVI connector 16 may block access to adjacent connector receptacles on the PC. The bulk of rigid body 20 can prevent other available ports on the PC from being used, or can make it extremely difficult if not impossible for a user to plug additional devices into the PC.
FIG. 3 shows an adjacent port being blocked by a bulky adapter. Ports 26, 26′ are plug receptacles on a PC or other device that have a spacing of S as shown. The spacing S is relatively tight, but is sufficient for several plugs such as DP connector 18 when the specification is followed. However, DP connector 18 is part of adapter body 24, which widens to support DVI connector 16 which is a wider connector. DVI extension end 28 of adapter body 24 infringes into the spacing above and between ports 26, 26′, as shown by the dashed lines extending above ports 26, 26′. While a very short second plug could theoretically be plugged into port 26′, the cable extending from the second plug would likely bump into DVI extension end 28 of adapter body 24. Thus second port 26′ is likely unusable since it is effectively blocked by DVI extension end 28 of adapter body 24.
FIG. 4 shows a DVI/DP adapter with a rotated DP connector. DVI connector 16 and DP connector 18 are rotated by 90 degrees to each other. DVI connector 16 is supported by DVI end 32 while DP connector 18 is supported by DP end 34 of adapter 30. Since DVI connector 16 and DP connector 18 are rotated by 90 degrees, ends 32, 34 also are in a rotated arrangement. This rotated arrangement may allow for better accessing of adjacent ports. However, the small length of adapter 30 may still cause adjacent ports on a PC or other device to be blocked. The rigid connection of ends 32, 34 may limit usefulness of adapter 30.
While such adapters and dongles are useful, blockage of adjacent ports on a PC are problematic. The adapters must widen to support the larger DVI connector 16, and this widening can block the space above and adjacent port on the PC. The limited flexibility of a dongle cable can still block adjacent ports, and the flexibility of the cable can cause the connection to loosen and fail over time.
What is desired is an adapter for video connectors such as DP and DVI. An adapter that does not block adjacent ports on a PC or other device is desired. An adapter with a larger end that can be easily moved away from a shadowing position is desired.